激光重熔对铁基/TiC复合涂层成形质量及性能研究

Study on Forming Quality and Properties of Fe-Tic Composite Coatings by Laser Remelting

为研究激光熔覆过程中重熔功率对熔覆层的形貌和性能影响,采用激光重熔技术,在Ti6Al4V钛合金表面制备了铁基/TiC复合涂层。采用着色渗透探伤剂和金相显微镜观察了熔覆层表面裂纹和气孔的分布情况,利用维氏硬度计和摩擦磨损测试仪表征了熔覆层的截面显微硬度和摩擦磨损性能。结果表明,重熔功率的增加能够有效地抑制熔覆层的裂纹和气孔;在力学性能方面,重熔后的熔覆层维氏硬度约是Ti6Al4V钛合金基体的8倍,当重熔功率为1200 W时,所制备的铁基/TiC复合涂层的平均维氏硬度达到最大值,约为1188 HV;此外,随着激光重熔功率增大,铁基/TiC复合涂层在磨擦磨损的过程中可以有效地阻止磨粒和摩擦副对熔覆层的微切削与塑性变形,同时,熔覆层的磨损量降低,摩擦系数降低。

In order to study the effect of remelting power on the morphology and properties of the cladding layer during laser cladding,the Fe-TiC composite coating was prepared on the surface of Ti6Al4Vtitanium alloy by laser remelting technology.The distribution of cracks and pores on the surface of the cladding layer was observed by means of tinted penetrant inspection agent and metallographic microscope.The microhardness and tribological properties of the cladding layer were characterized by Vickers hardness tester and tribological wear tester.The results show that the increase of remelting power can effectively suppress the cracks and pores in the cladding layer.In terms of mechanical properties,the Vickers hardness of the cladding layer after remelting is about 8times that of the Ti6Al4Valloy matrix.When the remelting power is 1200W,the average Vickers hardness of the Fe-TiC composite coating reaches the maximum value,which is about 1188HV.In addition,with the increase of laser remelting power,the Fe-TiC composite coating can effectively prevent the micro-cutting and plastic deformation of the cladding layer by abrasive particles and friction pairs in the process of friction wear,and the wear amount of the cladding layer decreases,and the friction coefficient decreases.